Missing Friends

So ive just been living with an issue where friends sometimes just disappear from the friends list in lobby. You cant even whisper the person when this happens. Though you can message them with bnet chat, and SEE their whispers to you ingame. right clicking the name and selecting whisper, shows “/w “ without their name.

Restarting the client SOMETIMES fixes the issue, but not always. Im posting because I restarted 4 times, and imediately tried to whisper somebody each time, but they were hidden every single time.

It would be nice if blizzard fixed the bug, but at this point if anyone has a better workaround Im all ears. If they give me the game-name I can copy that join and chat with them in-game but no whispers. It might be because I have 300+ friends, and if anyone can confirm, that would help I would be happy to prune the list.